1. Field of the invention
The invention herein relates to the treatment of glaucoma and other conditions of abnormally increased intraocular pressure. More particularly it relates to treatment by application of therapeutic compounds.
2. Description of the Prior Art
Glaucoma, the abnormally increased level of intraocular pressure, is one of the leading causes of blindness in the United States. Glaucoma has several related forms, but all involve the abnormal increase in intraocular pressure primarily by obstruction of the outflow of aqueous humor from the eye, or, less frequently, by overproduction of aqueous humor within the eye. Glaucoma in its various forms is widely described in the literature: see, e.g., Leibrandt, ed., Professional Guide to Diseases, 1203-1206 (1982) and Andreoli et al, eds., Cecil: Essentials of Medicine, 690-691 (1986). Glaucoma is primarily diagnosed by Schiotz or applanation tonometry, with gonioscopy, ophthalmoscopy, slit-lamp examination, fingertip tension and perimetry or visual field tests also being useful as diagnostic methods.
In the past treatment has involved administration of beta-blockers such as timolol to decrease aqueous humor production, epinephrine to lower intraocular pressure or diuretics such as acetazolamide, or administration of miotic eyedrops such as pilocarpine to facilitate the outflow of vitreous humor. Acute forms of glaucoma may require peripheral iridectomy surgery to relieve pressure where drug therapy is ineffective and the patient's vision is at immediate risk. Other forms of treatment have included physical or thermal destruction ("cyclo-destruction") of the ciliary body of the eye, commonly by surgery or application of a laser beam, cryogenic fluid or high frequency ultrasound. Each of these methods of destruction is costly and unduly invasive
(S)-1-(3-hydroxy-2-phosphonyl-methoxypropyl) cytosine [HPMPC], a phosphonylmethoxypropyl cytosine compound, is described in Maudgal et al., Invest. Ophthalmol. and Visual Sci., 32(6): 1816-1820 (1991). Descriptions of the use and efficacy of HPMPC with respect to treatment of viral diseases are described in Maudgal et al., supra; Neyts et al., Virology, 179(1): 41-50 (1990) and Andrei et al., Eur. J. Clin. Microbiol. Infect. Dis., 10(12): 1026-1033 (1991). Glaucoma, however, is not a viral condition, and therefore the treatments for the viral eye diseases discussed in the prior art have heretofore not been believed to be applicable to treatment of glaucoma.